Affinity chromatography is chromatography using a column filled with a ligand-immobilized carrier obtained by immobilizing a substance that specifically binds to a substance intended to be separated and purified (ligand), on an insoluble carrier. Affinity chromatography is used for, for example, separation and purification of biological substances such as proteins and nucleic acids (JP-A-H06-281638).
As the carrier for the filler for affinity chromatography, for example, particles obtained by crosslinking sugar chains (represented by agarose gel), or particles containing a synthetic polymer as a main component are used.
However, for use in bioseparation, a filler is usually used repeatedly. However, since there would be residual trace amounts of foreign materials in the filler even after purification operation, usually an operation known as cleaning in place (CIP) is carried out. In the CIP, a reagent capable of eluting foreign substances from the filler (CIP agent) is used. Examples of such reagents include alkaline liquids such as sodium hydroxide. In the case of using sodium hydroxide, foreign substances such as microorganisms, proteins, lipids and nucleic acids can be effectively removed.